We've all experienced the angst of a burned tongue, the
subsequent moaning and groaning about it, the diminished level of
joy when eating. And then, out of nowhere it seems, the tongue is
back and ready for action.

It's the miracle of life, um, kind of, at the cellular level, and
it's all thanks to stem cells.

Stem cells are super cool, like way-nerdy-sci-fi super cool, and
I'm disappointed that they really haven't got a fair shake from the
media. All we hear about on the news is the unrest related to
embryonic stem cells and research. Ok, step back and don't worry,
I'm not about to go on a political tirade, but I am going to use
taste to show just amazing stem cells are in your body and how they
are working for you right now.

To kick this off, it's important to realize that every single one
of your cells has the exactly the same DNA, and this is your
cookbook for making all the things your body needs. So if every
cell has the same cookbook then how in the worId do we have so many
different types of cells? Well, the straight-forward answer is that
different cell types pick and choose a unique combo of recipes
within the cookbook to make (each recipe is a gene). This picking
and choosing stage is highly regulated in your body and is called
Gene Expression.

So where do stem cells come in? They are like the culinary school
of cells, spitting out brand new cooks into brand new kitchens with
the whole cookbook at their disposal. And these new chefs, called
"precursor cells" start to get signals that show them what their
speciality will be and which recipes they will begin to use, and
which ones they will never use. As the chefs/precursor cells "learn
more" they start going down a specialty path, and no longer have
the ability to be a generalist, they become rather forever a
specialist. A pastry chef/muscle cell, a sushi chef/neuron and so
on.

This process happens in so many parts of your body, from the
liver, to the bone marrow, to the brain, and yes, even in your
taste buds. And it helps us to have a new supply of cells
throughout our lives, so that when cells die or are damaged we can
replace them and keep on keeping on.

Dr. Linda Barlow of the University of Colorado and the Rocky
Mountain Taste and Smell Center, kicked off the 8 am session this
morning with how this happens on the tongue. She and colleagues are
trying to figure out which cells in the taste bud are the precursor
cells, what kind of characteristics they have, and what specialty
cells they turn into.

She and her team have looked closely at a cell type that lives at
the very bottom of the taste bud and expresses the recipe for a
protein called "sonic hedge hog" Shh for short. Worth noting that I
use to love playing that video game. So they have a candidate
precursor cell, they know some of the characteristics and now they
are doing really cool tracking experiments to visualize what
happens to these Shh cells after they are born from stem cells. She
showed beautiful pictures of where they go in the taste bud and
based on which genes they start to use she can determine which
specialty taste cells they are destined to become.

Research like Dr. Barlow's on how taste cells are born and reborn
helps scientists not only understand more about the taste system in
development and repair, but it also sheds a lot of light on the
fascinating role of stem cells. Basic science like this is the
foundation for all the amazing discoveries in human health that
help us everyday, and will continue to be the foundation for the
amazing discoveries to come.

What a nice way to close a fantastic 2012 AChemS conference. It
makes me excited to get back in the lab with the team and get
cranking on discoveries of our own.